Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f68c652d28c54c1…

MALICIOUS

PDF

84.5 KB Created: 2021-10-09 12:25:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b40297a1dc3b55bd18fb4aa3421b3263 SHA-1: 333668b4bd585eef8b05fcd18f70d1ad6744b5c8 SHA-256: 0f68c652d28c54c18b5a2f8c62e883824bb0feade8ca5711b3b1e5664c59ef58
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload directories. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a campaign to distribute malicious content or manipulate search engine results. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://stgeorgedentalcare.in/ckfinder/userfiles/files/59708324496.pdf In PDF document text
    • https://nesbedcollege.com/singhania/downloads/file/35240158099.pdfIn PDF document text
    • http://sinners-party.de/media/file/59866115558.pdfIn PDF document text
    • http://mastervin.ru/files/file/wekorupawufobusito.pdfIn PDF document text
    • http://customize.fr/fckeditor/editor/filemanager/connectors/php/img/Editor/file/54511652495.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1614c8ae699eb2---ziravodazanumiti.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20211008084832.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210923015514_2053559937.pdfIn PDF document text
    • http://palakkadtourism.in/ckfinder/userfiles/files/jerejapip.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ba7d32d065---33317569073.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613316db5f7e5---lujexewijasejojafo.pdfIn PDF document text
    • http://stickers-moins-cher.com/userfiles/stickers-moins-cher.com/file/bofutalis.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/49015569008.pdfIn PDF document text
    • http://mirutte.com/newsfiles/files/63773370437.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/5388769116.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/30116522504.pdfIn PDF document text
    • http://naszemotyle.natura2000.pl/imgturysta/files/wokopubavalowomow.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/97830729297.pdfIn PDF document text
    • http://youzedu.com/ckimages/files/20211007153020829794.pdfIn PDF document text
    • http://www.cemeba.com/uploads/ckfinder/files/79674530184.pdfIn PDF document text
    • http://osteriadelcampanile.com/userfiles/files/lurag.pdfIn PDF document text
    • http://capthepcongtrinh.com/uploads/news/files/75301219820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=lord+of+the+rings+return+of+the+king+extended+streamPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e11b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE11B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f92d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF92D 19316 bytes
SHA-256: e9454be4cc1e95fe325d63b3320957739dbe1d233f763e4509094815fcfae9ec
font_02_sfnt_off00012ae2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE2 11004 bytes
SHA-256: 5aba0afbb3fa00ca352e80b7060cfea2663b3abae904f09f7803401815e7d1df